Field of the Invention
The invention relates to bags formed at least in part from open mesh materials and, more particularly, relates to form fill and seal (FFS) bags formed at least in part from an open mesh material formed from filaments, at least some of which are composite filaments that are thermally bondable to other filaments at at least some points of intersection. The invention additionally relates to methods of making those bags.
Description of Related Art
Synthetic open mesh materials are used in a wide variety of applications, including bags, silt fences and other barriers, bale wraps, and screens. These materials are formed with an open mesh pattern. Traditional mesh materials took the form of crossing threads or filaments that were woven or knitted together without bonding the filaments at their points of intersection. More recently, synthetic cross-laminated films have been introduced in which adjacent layers of slit and bi-axially stretched sheets are secured to each other through thermal bonding rather than through weaving or knitting. Many of the prior art open mesh materials lack dimensional stability. That is, they stretch relatively easily so that, when used in applications such as bags, they expand or bulge undesirably under the weight of the items in the bag. These materials also tend to be relatively weak. Other materials offer better dimensional stability or strength but are relatively heavy on a per area basis. These prior art materials are also relatively expensive to manufacture. Their range of applications also is limited due to limitations on possible variations of material properties.